Glucose Oxidase Research Articles

Hydrogel-Assisted Robust Supraparticles Evolved from Droplet Evaporation.

Supraparticles, formed through the self-assembly of nanoparticles, are promising contenders in catalysis, sensing, and drug delivery due to their exceptional specific surface area and porosity. However, their mechanical resilience, especially in dimensions spanning micrometers and beyond, is challenged by the inherently weak interactions among their constituent building blocks, significantly constraining their broad applicability. Here, we have exploited a robust supraparticle fabrication strategy by integrating hydrogel components into the assembly system and evaporating on the superamphiphobic surface. The resultant SiO2/SA (sodium alginate) supraparticles, achieved by evaporating a 15% volume fraction dispersion of SiO2 nanoparticles containing 18.46 mg/mL of sodium alginate and subsequently cross-linking with Ca2+, demonstrate mechanical robustness with a fracture force of 6.04 N, representing a mechanical strength enhancement of 60 times higher than that prior to the incorporation of the hydrogel component. The supraparticles maintain their original morphology after 30 min of ultrasonic treatment (200 W), demonstrating mechanical stability. This method exhibits generalizability, enabling the customization of supraparticles with various building blocks and hydrogel backbone materials. Based on such a methodology, we have synthesized enzyme-carrying supraparticles, further expanding the potential applications in intricate cascade reactions. The encapsulated glucose oxidase and horseradish peroxidase maintained their inherent reactivity, and such hydrogel-assisted robust supraparticles exhibited exceptional performance in accurate glucose assays, indicating great practical application in biocatalysis.

Glucose-Activated Janus Wound Dressing for Enhanced Management of Infected and Exudative Diabetic Wounds.

Diabetic wounds, often multifactorial and affecting multiple organs, pose substantial challenges to patient well-being, drawing significant interest in biomedical engineering. The demanding wound microenvironment, marked by heightened glucose levels, local exudate, and bacterial infections, emphasizes the pressing demand for advanced wound dressings to meet escalating clinical needs. Herein, a Janus wound dressing with an integration of an antimicrobial hydrophobic nanofiber layer and a 3D hydrophilic sponge was designed and prepared to manage and utilize wound exudate. The hydrophobic layer skillfully combined electrospun poly(ε-caprolactone) (PCL) nanofiber membranes (ENMs) and metal-organic frameworks (MOFs) with peroxidase-like properties by solvent etching, and glucose oxidase (GOx) was grafted through ligand interaction. GOx acts to consume glucose while modulating pH, thus suitable pH and self-supplied H2O2 were able to activate the catalytic activity of MOFs to generate •OH. Additionally, hydrophilic 3D sponges are constructed using gas foaming technology, which are tactfully combined with hydrophobic ENMs to form a Janus structure, which can transport exudate through the antimicrobial layer to the sponge layer, while sufficient glucose contact with GOx enhances the antimicrobial properties of the designed Janus wound dressing. Experimental results demonstrate the effectiveness of the cascade effect of GOx@PCL/MOF ENMs, ultimately releasing reactive oxygen species and exhibiting robust antibacterial properties. In vivo animal experiments reveal the ability of the Janus wound dressing to mitigate methicillin-resistant Staphylococcus aureus (MRSA) infections in the early stages, thereby expediting the wound healing process. In vivo animal study, the Janus wound dressing achieved a healing rate of 54% on day 3. Our findings underscore the substantial potential of the Janus wound dressings in promoting the healing of chronic diabetic wounds.

Cooperative Multiscale‐Assembly for Directional and Hierarchical Growth of Highly Oriented Porous Organic Cage Single‐Crystal Microtubes and Arrays

The directional assembly of porous organic molecules into long‐range ordered architectures, featuring controlled hierarchical porosity and oriented pore channels with defined spatial arrangements, is a fundamental challenge in chemistry and materials science. Herein, using porous organic cages as starting units, we present a cooperative multiscale‐assembly strategy enabling the simultaneous alignment of pore channels and directional hierarchical growth in a single step. At the microscopic level, we employed double solvents to manipulate the intermolecular packing of microporous tetrahedral [4+6] imine cages (CC1 and CC3), resulting in pore channel orientation. Concurrently, at the mesoscopic level, convective flow in the double‐solvent system directed the spatial distribution of nuclei species, followed by diffusion limited growth, leading to the directional formation of single‐crystal microtubes. By precisely controlling the direction of convective flow, the nanocages were successfully organized into 2D and 3D single‐crystal microtube arrays while maintaining oriented micropores. This hierarchical porous architecture enhanced mass transfer, as confirmed by adsorption measurements. Interestingly, such 3D hierarchical microtube arrays can be utilized to immobilize Pd clusters and enzymes (lipase or Glucose oxidase) within the micro‐ and macropores, respectively, showing a 3.8‐ to 4‐fold enhancement in one‐pot tandem reaction activity compared to physical mixtures of individual analogues.

Increasing the dual-enzyme cascade biocatalysis efficiency and stability of metal-organic frameworks via one-step coimmobilization for visual detection of glucose.

In biosensing analysis, the activity of enzyme systems is limited by their fragility, and substrates catalyzed by monoenzymes tend to undergo spontaneous decomposition during ineffective mass transfer processes. In this study, we propose a novel strategy to encapsulate the glucose oxidase and horseradish peroxidase (GOx&HRP) cascade catalytic system within the hydrophilic zeolite imidazole framework ZIF-90. By leveraging the specific pore structure of ZIF-90, we effectively immobilized GOx and HRP molecules in their three-dimensional conformations, which improved the catalytic activity of the encapsulated enzymes compared with that of free GOx and HRP in various harsh environments. Additionally, our strategy reduced the occurrence of ineffective mass transfer and enhanced the sensitivity of the biosensor through an enzyme cascade system. When this biosensor was applied to serum samples containing complex biological matrices, the degradation of GOx&HRP by various proteases and the surface adsorption of diverse biomolecules were effectively prevented, thereby generating stable and reliable signals of glucose levels. The sensor shows remarkable sensitivity and selectivity for determining glucose concentrations ranging from 0 to 2.5 μg ml-1, with a detection limit as low as 0.034 μg ml-1. Furthermore, we developed a paper-based colorimetric sensor utilizing GOx&HRP@ZIF-90 integrated with a smartphone platform for the visual detection of blood glucose.

The gas|liquid interface eclipses the liquid|liquid interface for glucose oxidase rate acceleration in microdroplets

The curious chemistry observed in microdroplets has captivated chemists in recent years and has led to an investigation into their ability to drive seemingly impossible chemistries. One particularly interesting capability of these microdroplets is their ability to accelerate reactions by several orders of magnitude. While there have been many investigations into which reactions can be accelerated by confinement within microdroplets, no study has directly compared reaction acceleration at the liquid|liquid and gas|liquid interfaces. Here, we confine glucose oxidase, one of life's most important enzymes, to microdroplets and monitor the turnover rate of glucose by the electroactive cofactor, hexacyanoferrate (III). We use stochastic electrochemistry to monitor the collision of single femtoliter water droplets on an ultramicroelectrode. We also develop a measurement modality to robustly quantify reaction rates for femtoliter liquid aerosol droplets, where the majority of the interface is gas|liquid. We demonstrate that the gas|liquid interface accelerates enzyme turnover by over an order of magnitude over the liquid|liquid interface. This is the first apples-to-apples comparison of reaction acceleration at two distinct interfaces that indicates that the gas|liquid interface plays a central role in driving curious chemistry.

Enhanced production of thermostable catalase for efficient gluconic acid biocatalysis

IntroductionThe demand for gluconic acid (GA) has risen recently, driven by its extensive applications in the food, healthcare, and construction industries. The biocatalysis of gluconic acid, facilitated by glucose oxidase and catalase, hinges on enzyme stability, significantly influencing catalytic efficiency. Nonetheless, catalase requires enhancements in thermal stability and activity to meet the requirements of practical applications.MethodsWe evaluated ten catalases expressed in Aspergillus niger, ultimately selecting the catalase from the thermophilic fungus Thermoascus aurantiacus, labeled as TaCat, for its superior thermal stability and operational performance. We further characterized the enzymatic properties of the recombinant catalase, focusing on its thermostability. Simultaneously, we used AlphaFold2 for structural predictions and conducted in-depth analyses via accelerated molecular dynamics simulations.Results and discussionWe successfully obtained a strain with the highest catalase activity by optimizing signal peptides and overexpressing the crucial heme synthesis enzyme. Enzyme production reached an impressive 321,779.5 U/mL in a 50-L fermenter. Our application studies confirmed the considerable advantages of TaCat in terms of GA production. In conclusion, TaCat, distinguished by its remarkable thermal stability and high activity, holds substantial potential for GA production.

Efficient calcium fumarate overproduction from xylose and corncob-derived xylose by engineered strains of Aureobasidium pullulans var. Aubasidani DH177

BackgroundXylose from lignocellulose is one of the most abundant and important renewable and green raw materials. It is very important how to efficiently transform xylose into useful bioproducts such as fumaric acid and so on.ResultsIn this study, it was found that the GC1 strain (∆gox, in which the GOX gene encoding glucose oxidase which could transform glucose into gluconic acid was removed) of A. pullulans var. aubasidani DH177 had the high ability to utilize xylose and corncob-derived xylose with CO2 fixation derived from CaCO3 to produce calcium fumarate. Overexpression of the XI gene encoding xylose isomerase, the XK gene encoding xylose kinase and the TKL gene coding for transketolase made the strain TKL-4 produce 73.1 g/L of calcium fumarate from xylose. At the same time, the transcriptional levels of the key ASS gene coding for argininosuccinate synthase and the ASL gene coding for argininosuccinate lyase in the ornithine-urea cycle (OUC) were also obviously enhanced. The results also demonstrated that the TKL-4 strain could produce more calcium fumarate from xylose and corncob-derived xylose than from glucose. During 10-liter fermentation, the TKL-4 strain could produce 88.5 g/L of calcium fumarate from xylose, the productivity was 0.52 g/h/L. Meanwhile, it could yield 85.6 g/L of calcium fumarate from corncob-derived xylose and the productivity was 0.51 g/h/L. During the same fermentation, the TKL-4 strain could transform the mixture containing 75.0 g/L glucose and 45.0 g/L xylose to produce 78.7 ± 1.1 g/L calcium fumarate.ConclusionsThis indicated that the TKL-4 strain constructed in this study indeed could actively transform xylose and corncob-derived xylose into calcium fumarate through the green ways.

Advances in CuO Nanostructure-Based Glucose Biosensors: From Enzymes to Direct Oxidation

Copper oxide (CuO) nanostructures have gained popularity in glucose biosensor development due to their excellent electrochemical properties, affordability and ease of fabrication. This review examines the progress of glucose biosensors based on CuO nanostructures and shows differences between enzyme-based and enzyme-dependent systems. Enzyme-based glucose oxidase sensors offer high specificity but are hampered by difficulties associated with enzyme stability at different temperatures, pH and interfering inhibitors. Unlike nonenzyme-based sensors, those using glucose oxidation directly offer high sensitivity and long working life but are struggling with specificity. The main drivers of these sensors are nanostructure morphology, synthesis techniques, surface modifications and electrode materials. The switch from more conventional CuO to sophisticated nanostructures significantly improved the sensitivity and durability of the sensor. This research focuses on optimizing these variables to address existing limitations and to advance CuO nanostructures as leads for next-generation glucose biosensing technologies.

Neonatal Hypoglycaemia Management Guideline appraisal using the AGREE II instrument and report of variations in unit guidelines in Australia and New Zealand.

To assess the quality and rigour of Neonatal Hypoglycaemia guidelines used in the major Australian and New Zealand neonatal care centres. To compare and highlight any major differences in management guidelines between centres. All level III NICUs in Australia and New Zealand were invited to participate. The AGREE II (Appraisal of Guidelines, Research & Evaluation) was used to critically appraise the guideline for the management of neonatal hypoglycaemia. Recommendations regarding definition, treatment, method of testing and admission criteria were compared from the guidelines provided. Neonatal Hypoglycaemia guidelines were received from 19 of the 29 invited hospitals; two guidelines were excluded as the hospitals providing these guidelines did not provide care for inborn neonates. None of the 17 guidelines received a standardised score of 50% or higher on all six domains of the AGREE II tool. The mean scores of each of the AGREE II domains were as follows: Scope and Purpose 76%; Stakeholder Involvement 41%; Rigour of Development 20%; Clarity of Presentation 66%; Applicability 30% and Editorial Independence 0.1%. The glycaemic threshold defining hypoglycaemia varied between 2.0 and 2.6 mmol/L in the guidelines. True blood glucose using either a glucose oxidase method or blood gas analyser was recommended as the first line test in 35% of the guidelines. Fifteen of the 17 guidelines recommended buccal gel as first-line treatment of hypoglycaemia. Neonatal Hypoglycaemia guidelines are of varying methodological quality. There are inconsistences in the management of hypoglycaemia across neonatal units in Australia and New Zealand.

Directionally co-immobilizing glucose oxidase and horseradish peroxidase on three-pronged DNA scaffold and the regulation of cascade activity

In traditional multienzyme random co-immobilization, it is difficult to precisely locate and regulate the relative positions between two enzyme molecules, resulting in low cascade efficiency between the two enzymes and limiting the application of multienzyme cascade catalysis technology. This study prepared PVAC@Y-dsDNA@GOD/HRP magnetic co-immobilized multienzyme by constructing a three-pronged DNA scaffold for co-coupling glucose oxidase (GOD) and horseradish peroxidase (HRP), which achieved directional co-immobilization of dual enzymes and precise regulation of inter-enzyme distance. Compared with traditional random co-immobilization of multienzyme, PVAC@Y-dsDNA@GOD/HRP could shorten the distance between GOD and HRP to the nanoscale and form substrate channeling, which greatly improved the cascade activity between the two enzymes. The inter-enzyme spacing between GOD and HRP could be precisely regulated by changing the length of DNA strands. When the inter-enzyme spacing was 10.08 nm, PVAC@Y-dsDNA@GOD/HRP exhibited high cascade activity of 707 U/mg. The inter-enzyme spacing that was too large or too small would reduce the cascade activity, indicating a distance-dependence of multienzyme cascade activity. PVAC@Y-dsDNA@GOD/HRP showed good reusability, indicating that the three-pronged DNA scaffold constructed by DNA double strands hybridization could firmly immobilize enzyme on carrier, with less enzyme leakage.

Active and Intelligent Packaging Technology for Hilsa (Tenualosa ilisha)

During long marketing chain, Hilsa rapidly lose quality even in chilled condition. When purchase, consumers often get confused to differentiate between stale and fresh Hilsa. Four different active packages; namely, G1 (commercial oxygen absorber + nisin), G2 (commercial oxygen absorber + chitosan), G3 (glucose oxidase + nisin), and G4 (glucose oxidase + chitosan) were manufactured and tested to overcome these troubles. In case of thiobarbituric acid reactive substances (TBARS) content, G3 had lowest TBARS value followed by G4, G1 and G2, while control samples had the highest TBARS value. In regard to protein retention, all active packagings showed higher protein retention than control. Bacterial load was highest (4.87 log CFU/g) in control samples while active packagings had 2.29-3.96 log CFU/g. In case of total volatile basic nitrogen (TVB-N) content, G3 had minimum TVB-N content followed by G4, G1 and G2, while control samples had the highest TVB-N content. Phenol red dyed paper strips, which were used as intelligent indicator, did not change bright orange colour in active packages while turned into yellow and pale yellow in control and unacceptable samples, respectively. Active packagings were able to keep quality of Hilsa good for at least 28 days. Described active packagings technologies should be applied to enhance shelf-life of fishery products.

Ligand engineering boosts catalase-like activity of gold nanoclusters for cascade reactions combined with glucose oxidase in ZIF-8 matrix

Ligand engineering boosts catalase-like activity of gold nanoclusters for cascade reactions combined with glucose oxidase in ZIF-8 matrix

Entropy-driven self-assembled enzyme-DNA nanomatrix cascade DNAzyme-CRISPR/cas system for multiplexed enhancement of self-powered sensing platform for protein detection

Clustered Regularly Interspaced Short Palindromic Repeats and CRISPR-associated Proteins (CRISPR/Cas) system can accurately identify and cleave target DNA sequences, while the effective combination of DNA nanomatrix and entropy-driven self-assembled enzymes can significantly enhance the sensitivity, stability, and diversified functionality of sensors through highly ordered molecular arrangement and spontaneous efficient assembly processes. Herein, a carbon-encapsulated MoS2 hollow nanorod (C-MoS2) with excellent conductivity and multiple active sites is used to construct bioanode of biofuel cell by integrating it with an entropy-driven self-assembled enzyme-DNA nanomatrix cascade DNAzyme-CRISPR/Cas system. When thrombin binds aptamer, it exposes the trigger strand on the anode, initiating chain displacement. This activates DNAzyme, triggering a cascade reaction that cleaves and releases the probe strand. The probe then binds CrRNA, forming a multimeric complex with Cas protein.When non-specific cleavage of the single strand occurs, it leads to the release of glucose oxidase (GOD) from the DNA matrix and causes a significant decrease in the value of the system's open-circuit voltage (EOCV). The EOCV values show a good negative correlation with the concentration of thrombin (TB) in the range of 0.00001–100 nM, achieving a limit of detection of 3.55 fM (S/N = 3).

Injectable Multifunctional Hyaluronan based Hydrogel Suppressing the Excessive Glucose and Reactive Oxygen Species in Diabetic Wound Treatment

In diabetic wounds, the overlapping presence of excessive glucose and reactive oxygen species (ROS) forming a vicious cycle that severely impedes the wound healing process. Despite advancements in wound care, current treatments often limit in addressing these two critical factors simultaneously. To address these challenges, this study introduces a multifunctional hydrogel system capable of dual regulation of excessive glucose and ROS levels in a hyperglycemic environment, while also provide a platform with favorable properties that support wound healing. First, by modifying hyaluronic acid (HA) chains with vinyl sulfone and thiol functional groups, the resulting hydrogel exhibited tunable gelation time, elastic modulus, and degradation rates, making it adaptable for diabetic wound management. Notably, this hydrogel allows for precise glucose and ROS regulation by encapsulating glucose oxidase (GOx), horseradish peroxidase (HRP), and tannic acid (TA) within the HA hydrogel matrix. It was verified that the hydrogels could reduce the glucose levels to desired concentration by varying the encapsulated GOx content. Simultaneously, the combined ROS-scavenging effect of HRP and TA effectively addressed the excessive ROS problem. Specifically, H2O2 generated from the GOx-glucose reaction was consumed in the HRP-mediated polymerization of TA, and free radicals (OH•, DPPH) were scavenged up to 70% by TA. Due to the glucose and ROS regulation properties, this hydrogel system was able to promote the proliferation and migration of human dermal fibroblast in a hyperglycemic environment. Overall, this study offers a simple and effective approach to regulate the excessive levels of glucose and ROS in a hyperglycemic condition, which has potential in creating a multifunctional platform for diabetic wound treatment.

Revised safety evaluation of the food enzyme glucose oxidase from the genetically modified Trichoderma reesei strain AR-352.

The food enzyme glucose oxidase (β-d-glucose: oxygen 1-oxidoreductase; EC 1.1.3.4) is produced with the genetically modified Trichoderma reesei strain AR-352 by AB Enzymes GmbH. In a previous opinion, the Panel on Food Contact Materials, Enzymes and Processing Aids of the European Food Safety Authority could not conclude on the absence of recombinant DNA from the production strain in the food enzyme due to uncertainties about the limit of detection of the applied methodology. New data provided by the applicant showed that no DNA from the production strain was found in the food enzyme with a limit of detection meeting the requirements of the applicable guidance. Based on the new data provided, the Panel concludes that this food enzyme is free from recombinant DNA from the production strain.

Low-cost optical fiber multimode interference biosensor based on a glucose sensitive Glucose-Oxidase enzyme thin-film.

Low-cost optical fiber multimode interference biosensor based on a glucose sensitive Glucose-Oxidase enzyme thin-film.

High‐Pressure Reactor Technology for Aerated Biotransformations

AbstractUtilizing pressure as a process parameter can make biotechnological processes more efficient and attractive compared to established ones. This paper presents a high‐pressure reactor setup for enzymatically catalyzed gas–liquid reactions, which can be operated up to 15.0 MPa. The reactor is equipped with optical measurement technology for inline and in situ monitoring of the oxygen concentration under high‐pressure conditions. The setup is characterized by assessing the influence of the process parameter pressure on the conversion of the glucose oxidation to d‐glucono‐δ‐lactone by immobilized glucose oxidase. The study demonstrates that the increased oxygen availability due to higher solubility reduces the reaction time in a batch reactor from 270 to 90 min.

Amplified Cascade Catalysis for RAFT Polymerization.

We report a conceptually new amplified cascade catalysis that converts oxygen to hydroxyl radical for controlled RAFT polymerization. This catalysis consists of two sequential reactions, deoxygenation catalyzed by glucose oxidase and Fenton reaction catalyzed by ferrocene. The two catalysts can communicate with each other, leading to ferrocene recycling and hence amplification in radical generation. Ferrocene recycling was confirmed by UV-vis spectroscopy, molecular docking simulation, electron paramagnetic resonance spectroscopy, as well as polymerization studies. This catalysis was applied to RAFT polymerization of various monomers, yielding well-defined homopolymers and diblock copolymers with controlled molecular weights and low dispersities. Poly(N,N-dimethyl acrylamide) with molecular weight over 1 million g mol-1 was also successfully synthesized under ambient conditions. Ferrocene-functionalized microspheres were prepared and used as recyclable Fenton catalyst for five consecutive polymerizations with minimal declination in monomer conversion, which further improved the ecofriendly character of this polymerization methodology.

Carbonised Typha tassel-modified enzymatic electrodes for ferrocene-mediated glucose biosensor and glucose/air biofuel cell applications

This study demonstrates the application of carbonised Typha tassel (CTT) in ferrocene-mediated enzymatic glucose biosensing and enzymatic biofuel cell (EnBFC) applications. Typha tassel was carbonised under an inert atmosphere to obtain conductive CTT which was then mixed with an effective electron transfer mediator, ferrocene (Fc) obtaining a redox-active electrode material. The successful immobilisation of the glucose oxidase (GOx) enzyme was performed on a CTT-Fc modified screen-printed electrode followed by a chitosan protective coating. The resulting enzymatic electrode was electrochemically characterised as a glucose biosensor with a working range of 0–10 mM and LOD and LOQ values of 0.19 mM and 0.56 mM, respectively. The developed glucose biosensor also showed good reproducibility and reusability with RSD% values of 6.68 % and 8.75 %, respectively. Furthermore, a real sample demonstration was performed using commercial jam samples with good recovery values. Finally, an EnBFC demonstration was performed using the enzymatic biosensor as an anode and a non-enzymatic cathode prepared using platinum black on gas diffusion carbon electrodes reaching a maximum power density of 3.6 µW cm−2. This study shows the promise of CTT as an alternative to conventional materials in enzymatic biosensor and bioelectronic applications as a suitable, cheap, and sustainable material.

Magnetically Responsive Enzyme and Hydrogen-Bonded Organic Framework Biocomposites for Biosensing.

The one-pot synthesis of multicomponent hydrogen-bonded organic framework (HOF) biocomposites is reported. The co-immoblization of enzymes and magnetic nanoparticles (MNPs) into the HOF crystals yielded biocatalysts (MNPs-enzyme@BioHOF-1) with dynamic localization properties. Using a permanent magnet, it is possible to separate the MNPs-enzyme@BioHOF-1 particles from a solution. Catalase (CAT) and glucose oxidase (GOx) show increased retention of their activity when coimmobilized with MNPs. MNPs-GOx@BioHOF-1 biocomposites are used to prepare a proof-of-concept glucose microfluidic biosensor, where a magnet allow to position and keep in place the biocomposite inside a microfluidic chip. The magnetic response of these biocatalysts can pave the way for new applications for the emerging HOF biocomposites.